SYNTHESIS OF THE POTASSIUM-SALT OF 2,3,4,5-TETRAHYDRODIPICOLINIC ACID, A KEY INTERMEDIATE IN THE DIAMINOPIMELATE PATHWAY TO L-LYSINE

The potassium salt (13) of 2,3,4,5-tetrahydrodipicolinic acid, a key intermediate in the diaminopimelate (DAP) pathway to L-lysine (7), has been prepared by elimination of p-toluenesulphinic acid from the N-toluenesulphonyl derivative (12) of dimethyl cis-piperidine-2,6-dicarboxylate with simultaneous cleavage of the ester groups. 2,3,4,5-Tetrahydrodipicolinic acid exists in solution in equilibrium with the corresponding enamine (15) and an open chain form (14), and serves as a substrate for meso-DAP dehydrogenase on the biosynthetic pathway to L-lysine (7).